Community Forums

luqutus · 12-28-2015, 08:21 AM

1999 country coach. manual says to use dexron III in hydraulic system that runs the engine fan and power steering. since they no longer dexron III what has any one been using. how about Allison's transynd?

nctox · 12-28-2015, 08:28 AM

Good question. I just noticed that the local Advance Auto Parts store carries Dexron IV. Anyone know a reason this wouldn't be a good substitute?

Crasher · 12-28-2015, 08:30 AM

Dextron IV or V would be a good choice, as it meets all of the D. III specs.

JRPA · 12-28-2015, 08:36 AM

The Dexron IV and V both should state that they meet all the Dexron III requirements right on the container. I don't know if they all say that or not but I always look for the notation stating it meets the Dexron III specs before I purchase it just to be sure.

edgray · 12-28-2015, 08:39 AM

Quote:

Originally Posted by nctox

Good question. I just noticed that the local Advance Auto Parts store carries Dexron IV. Anyone know a reason this wouldn't be a good substitute?

I don't know what fluid you guys are calling "IV" or "V", but the GM certified fluid that replaced Dexron III is called Dexron "VI" or Dexron 6.

Likewise, I don't know if the question posed by the OP about his hydraulic fan and PS systems will be similarily affected, but Allison issued a warning to owners of their trannies using Dexron III that specifically warns them NOT to use Dexron VI, because it was found to damage the seals used in those older trannies.

TO THE OP: If I needed to replace the fluid in a system designed
for Dexron III, I would definitely use TranSynd or any of the other brands of TES-295 approved fluids. There is a list of the TES-295 fluid brands on the Allison website, or you can read more about this issue in the Allison forum here on iRV2.com.

chuckbear · 12-28-2015, 10:12 AM

I find Dexron III at just about any auto parts store with no problem. Just bought some for my levelers last week at Autozone. Chuck

vapor3000 · 12-28-2015, 10:23 AM

Vavoline makes Dextron III, IV and V. They are all interchangable. Auto Zone carries on a regular basis.

deandec · 12-28-2015, 11:02 AM

I changed my DIII to Transynd.

Did not see any additional benefit for the premium paid.

Oil analysis says tranny wear is fine so the DIII did no damage.

Would like to get that premium price for Transynd back.

gemini5362 · 12-28-2015, 02:08 PM

Quote:

Originally Posted by luqutus

1999 country coach. manual says to use dexron III in hydraulic system that runs the engine fan and power steering. since they no longer dexron III what has any one been using. how about Allison's transynd?

It probably will not matter for that particular usage. In my allegro bus they changed from hydraulic fluid in the engine fan and power steering pump to 30 weight motor oil. Their was some overheating problems in a few years and one of the fixes was to go to oil because it was felt the hydraulic fluid was getting too hot and thinning out. If you can put motor oil in there probably not going to be too big an issue of what hydraulic fluid you use. This is only for the hydraulics that drive your coolant fan. NOT for your transmission.

Mr_D · 12-28-2015, 02:34 PM

Quote:

Originally Posted by chuckbear

I find Dexron III at just about any auto parts store with no problem. Just bought some for my levelers last week at Autozone. Chuck

GM no longer tests nor approves Dexron III fluids so you have no way of knowing what you're buying.

POPPASMURF · 12-28-2015, 02:35 PM

People should understand that Dexron 111 is no longer certified by GM. Therefore anyone can put any product they wish in any container and call it Dexron 111. Some companies can be trusted, some maybe not so much.

Mr_D · 12-28-2015, 02:37 PM

Quote:

Originally Posted by vapor3000

Vavoline makes Dextron III, IV and V. They are all interchangable. Auto Zone carries on a regular basis.

Not true if it's going in an Allison trans. The seals in the Allisons are NOT compatible with Dexron (no "t" in the name) IV and possibly not V.

docj · 12-28-2015, 02:38 PM

Quote:

Originally Posted by deandec

I changed my DIII to Transynd.

Did not see any additional benefit for the premium paid.

Oil analysis says tranny wear is fine so the DIII did no damage.

Would like to get that premium price for Transynd back.

Although you may not have been changing the transmission fluid at regular intervals when you had it filled with DIII, Allison recommended changing that fluid every couple of years. With Transynd the recommended intervals have now been raised to hundreds of thousands of miles; with fluid sampling most RVers will never need to change their transmission fluid once it is filled with Transynd.

Furthermore, many MH owners reported substantially cooler transmission fluid operating temperatures after changing to Transynd. If your MH has a Silverleaf or Aladdin the transmission fluid temperature can be read with digital accuracy and changes are readily observable.

There's no reason to have expected any observable performance change with Transynd other than the change in coolant temp. It's not going to make your coach accelerate any faster.

mel s · 12-28-2015, 02:53 PM

Quote:

Originally Posted by luqutus

1999 country coach. manual says to use dexron III in hydraulic system that runs the engine fan and power steering. since they no longer dexron III what has any one been using. how about Allison's transynd?

luqutus
I don't know about the hydraulic system that runs the engine fan and power steering,
Sorry.

However any synthetic automatic transmission fluid, (ATF), which meets TES 295 specifications is approved by Allison for use in the M3060 Allison 6 speed transmissions used in many, (most?), diesel powered motor homes.
See: On-Highway Fluids

I use Mobil Delvac Synthetic ATF™ in mine.

For information about what ATF you should use in your Allison, (and how often it should be changed), call Allison at 800-252-5283 with your transmission serial number and ask.

Mel
'96 Safari, 145k miles